If you buy a used Mac, there are many things you need to check out before completing the purchase. You can run hardware diagnostics and check the battery and hard drive's health. You should carefully inspect the screen, keyboard and other parts. It is also very important that you check for a firmware password and see if your Mac is connected to iCloud. The best place to buy is from Apple's refurbished store, but you can also find used Macs at some well-known retailers, as well as eBay and CraigsList. Be very careful to avoid fraud and protect yourself. When you get the new old Mac, wipe it and start fresh.
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